1. Field of the Invention
The present invention relates to a mobile communication system, and in particular to an apparatus and method for processing a data call on 2.5 generation mobile communication network.
2. Background of the Related Art
A related art data service on a 2.5 generation mobile communication network allots certain channels and provides circuit or packet data service paths through signaling, as defined at IS-658, IS-707(TIA/EIA), Q.933 and Q.931(ITU-T), which are the standard protocols between a switching system and an Interworking Function (IWF).
As depicted FIG. 1, the related art mobile network comprises a subscriber terminal 1, a Base Tranceiver Subsystem/Base Station Controller (BTS/BSC) 2, a Mobile Switch Center (MSC) 3 and an IWF 4. The MSC 3 includes a subscriber module 3-1 and a frame relay interface module 3-2.
FIG. 2 is a flow chart illustrating a process of the related art data call processing on the 2.5 generation mobile communication network. As shown in FIG. 2, an originating data call is inputted to the BTS/BSC 2 from a subscriber terminal as shown in step S1. The BTS/BSC 2 then requests a data call setting of the MSC 3, as shown in step S2.
The subscriber module 3-1 of the MSC 3 recognizes the call as either a circuit or packet data call after analyzing a service option set by the subscriber terminal. The MSC 3 then requests a connection with the IWF through the frame relay interface module 3-2, in order to provide a data path through the IWF 4, as shown in step S3.
Specifically, a frame relay interface module 3-2 requests the call setting to the IWF 4 in accordance with a defined procedure of Q.933, which is the frame relay interface signal standard between the IWF 4. It also allots the HO channel as the bearer channel and provides the circuit or packet data call path, as shown in step S4.
The protocol required for circuit or packet data service between the terminal and the IWF 4 sets the physical path. When circuit data service is required, the IWF 4 allots modem resources in order to provide circuit data service. The IWF further sets a data path through an Integrated Service Digital Network Primary Rate Interface (ISDN PRI) module (not shown) and signaling inside of the MSC 3, and thus provides circuit data service.
When, on the other hand, packet data call is required, the IWF 4 provides packet data service through a router connected to itself.
If, however, there is a MSC 3 without the IWF 4, data service is impossible, and the subscriber module 3-1 of the pertinent MSC 3 accordingly rejects all inputted data calls as shown in step S2xe2x80x2.
In addition, a call processing circuit or state managing circuit (not shown) of the frame relay interface module 3-2 checks a device state of the frame relay interface module, a bearer channel state, a signal channel state, and an H0 channel occupation state. When an overload or error occurs on the frame relay interface module 3-2, it rejects all calls received from the mobile communication subscriber are rejected, as shown in step S3xe2x80x2.
When an overload or error occurs on the IWF 4, one of the call processing circuit and state managing circuit of the frame relay interface module detects the error during signaling with the IWF 4, and rejects the call as shown in step S4xe2x80x2.
As described above, in the related art technology, when the IWF of a mobile communication network is in an abnormal or overload state, or if a frame relay module of a MSC is in an overload or error state, wireless data service can not be provided, because a MSC without the IWF cannot set data service itself.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
It is an object of the present invention to provide an apparatus and a method for processing data call on mobile communication network which is capable of using switch resources and IWF resources of the other MSC by connecting a plurality of MSC each other and making incoming/outgoing call processing possible each other when overload or error occurs on a MSC or IWF in data call attempting.
The other object of the present invention is to provide wireless data set,ice on a MSC without IWF by using IWF resources of other MSCs.
Another object of the present invention is to provide data service continuously when change or testing of operation equipment of an MSC is performed by getting the data route other MSC.
To achieve above-mentioned objects, an apparatus for processing data call on mobile communication network comprises a first MSC which performs outgoing to a second switch set in advance when its data service is impossible, and the second MSC incoming-performs call from the first MSC and provides data call path between IWF (Interworking Function).
In addition, to achieve above-mentioned objects, data call processing process on mobile communication network comprises recording process which checks overload or error occurrence on the first MSC and records whether data service is possible or not on database, judging process which judges whether data service is possible or not by searching the database after data call setting requirement is inputted, requesting process which requests outgoing to the set second MSC when data service of the first MSC is impossible, and providing process which incoming-performs the call from the first MSC, sets IWF and data call path connected to the second MSC, and provides data service.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.